Alleyn was still absorbed in this evidence of Roberts’s industry when the author himself came in.
“Inspector Alleyn, I believe,” said Roberts.
With a slight effort Alleyn refrained from answering “Dr. Roberts, I presume.” He closed the book over his thumb and came forward to meet the anæsthetist. Roberts blinked apprehensively and then glanced at the volume in the inspector’s hand.
“Yes, Dr. Roberts,” said Alleyn, “you’ve caught me red-handed. I never can resist plucking from bookshelves and I was so interested to see that you yourself wrote.”
“Oh,” answered Roberts vaguely, “the subject interests me. Will you sit down, inspector?”
“Thank you. Yes, the problems of heredity have an extraordinary fascination, even for a layman like myself. However, I haven’t come here to air my ignorance of your country, but to try and fill out some of the blanks in my own. About this O’Callaghan business— ”
“I am extremely sorry to hear of the result of the autopsy,” said Roberts formally. “It is terribly distressing, shocking, an irreplaceable loss.” He moved his hands nervously, gulped, and then added hurriedly: “I am also exceedingly distressed for more personal reasons. As anæsthetist for the operation I feel that I may be held responsible, that perhaps I should have noticed earlier that all was not well. I was worried, almost from the start, about his condition. I said so to Sir John and to Thoms.”
“What did they answer?”
“Sir John was very properly concerned with his own work. He simply left me to deal with mine, after, I think, commenting in some way on my report. I do not remember that Thoms replied at all. Inspector Alleyn, I sincerely hope you are able to free Sir John from any possibility of the slightest breath of suspicion. Any doubt in that direction is quite unthinkable.”
“I hope to be able to clear up his part in the business as soon as the usual inquiries have been made. Perhaps you can help me there, Dr. Roberts?”
“I should be glad to do so. I will not attempt to deny that I am also very selfishly nervous on my own account.”
“You gave no injection, did you?”
“No. I am thankful to say, no.”
“How was that? I should have imagined the anæsthetist would have given the camphor and the hyoscine injections.”
Roberts did not speak for a moment, but sat gazing at Alleyn with a curiously helpless expression on his sensitive face. Alleyn noticed that whenever he spoke to Roberts the doctor seemed to suppress a sort of wince. He did this now, tightening his lips and drawing himself rigidly upright in his chair.
“I–I never give injections,” he said. “I have a personal and very painful reason for not doing so.”
“Would you care to tell me what it is? You see, the fact that you did not give an injection is very important from your point of view. You did not see the patient while he was conscious and so — to be frank — could hardly have poured hyoscine down his throat without someone noticing what you were up to.”
“Yes. I see. I will tell you. Many years ago I gave an overdose of morphia and the patient died as the result of my carelessness. I–I have never been able to bring myself to give an injection since. Psychologically my behaviour has been weak and unsound. I should have overcome this repulsion, but I have been unable to do so. For some time I even lost my nerve as an anæsthetist. Then I was called in for an urgent case with heart disease and the operation was successful.” He showed Alleyn his stethoscope and told him its history. “This instrument represents an interesting experiment in psychology. I began to mark on it all my successful cases of heart disease. It helped enormously, but I have never been able to face an injection. Perhaps some day I may. Sir John is aware of this — peculiarity. I told him of it the first time I gave an anæsthetic for him. It was some time ago in a private house. He very thoughtfully remembered. I believe that in any case he prefers to give the hyoscine injection himself.”
He turned very white as he made this unhappy confession, and it was curious to see how, in spite of his obvious distress, he did not lose his trick of formal phraseology.
“Thank you so much, Dr. Roberts,” said Alleyn gently. “We need not trouble any more about that. Now, you say you were worried almost from the start about Sir Derek’s condition. Would you describe this condition as consistent with hyoscine poisoning?”
“Ever since Thoms rang up I have been considering that point. Yes, I think I should. In the light of the autopsy, of course, one is tempted to correlate the two without further consideration.”
“Did you notice any definite change in the patient’s condition, or did the same symptoms simply get more and more acute, if that’s the right way of putting it?”
“The pulse was remarkably slow when I first examined him in the anæsthetising-room. The condition grew steadily more disquieting throughout the operation.”
“But, to stress my point, there was no decided change at any time, only a more or less gradual progression.”
“Yes. There was perhaps a rather marked increase in the symptoms after Sir John made the first incision.”
“That would be after he had given the hyoscine injection, wouldn’t it?”
Roberts glanced at him sharply.
“Yes, that is true,” he said quickly, “but do you not see, the small amount Sir John injected — a hundredth of a grain, I think it was — would naturally aggravate the condition if hyoscine had already been given?”
“That’s perfectly true,” agreed Alleyn. “It’s an important point, too. Look here, Dr. Roberts, may I take it that it’s your opinion that hyoscine — a fatal amount — was somehow or other got into the man before the operation?”
“I think so,” Roberts blinked nervously. He had that trick of blinking hard, twice — it reminded Alleyn of a highly strung boy. “Of course,” he added uneasily, “I realise, inspector, that it would probably be to my advantage if I said that I thought the lethal dose was given when the patient was on the table. That, however, is, in my opinion, most improbable.”
“I must here trot out my customary cliché that it is always to an innocent person’s advantage to tell the truth,” Alleyn assured him. “Do you know, it’s my opinion that at least two-thirds of the difficulties in homicidal cases are caused by innocent asses lying for all they’re worth.”
“Indeed? I suppose there is no possibility of suicide in this instance?”
“It seems very unlikely so far. Why? How? Where’s the motive?”
“There need not necessarily be any usual motive.” Roberts hesitated and then spoke with more assurance than he had shown so far. “In suggesting this,” he said, “I may be accused of mounting my special hobbyhorse. As you have seen, I am greatly interested in hereditary taints. In Sir Derek O’Callaghan’s family there is such a taint. In his father, Sir Blake O’Callaghan, it appeared. I believe he suffered at times from suicidal mania. There has been a great deal of injudicious inbreeding. Mark you, I am perfectly well aware that the usual whole-hearted condemnation of inbreeding is to be revised in the light— ”
He had lost all his nervousness. He lectured Alleyn roundly for ten minutes, getting highly excited. He quoted his own works and other authorities. He scolded the British public, in the person of one of their most distinguished policemen, for their criminal neglect of racial problems. Alleyn listened, meek and greatly interested. He asked questions. Roberts got books from his shelves, read long passages in a high-pitched voice, and left the volumes on the hearthrug. He told Alleyn he should pay more attention to such things, and finally, to the inspector’s secret amusement, asked him flatly if he knew, if he had taken the trouble to find out, whether he himself was free from all traces of hereditary insanity.